Currently, there are various communication networks, e.g., Global System for Mobile Communication (GSM) network, different Code Division Multiple Access (CDMA) networks (e.g., Wideband Code Division Multiple Access (WCDMA) network and CDMA 2000 network), and the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) network. Along with the increase in the number of the communication networks and the geographical coverage of each communication network, power consumption of a base station becomes more important. Hence, it is necessary to reduce the power consumption of the base station.
In prior art, some energy-saving operations, e.g., a power-off operation, may be performed on the base station in accordance with the number of connected UEs in a cell. It is impossible for the base station to acquire the number of idle UEs within its coverage, so the user experience and services initiation for the idle UEs may probably be adversely affected by these operations. The connected UE refers to a UE in a connected state, while the idle UE refers to a UE in an idle state. The UE is also known as a terminal.
In an LTE network, the idle UE within an LTE cell may perform cell selection or cell re-selection. After the cell selection or cell-reselection, the idle UE may reside in a certain cell, and monitor system information and paging information. Except updating a Tracking Area (TA), the UE does not notify a resident cell of its existence. In other words, in most cases, the base station does not know the number of the idle UEs which reside in the base station. For a broadcast message from the LTE base station, System Information Blocks (SIBs) 3 to 8 are all configured to the cell selection or cell re-selection of the idle UE. In the case that the base station cannot know whether or not there are idle UEs residing therein or the number of the idle UEs residing therein, it is impossible for the base station to effectively reduce an overhead of the system information. In addition, in the case that the base station is capable of knowing a condition of the idle UE residing therein, it is able to ensure the service quality in a better manner during the energy-saving operations such as the power-off operation or an operation of stopping the transmission of some information. Further, in the case that the base station is capable of knowing identifiers of the idle UEs residing therein and reporting the identifiers to a network side, the network side may perform an accurate paging operation at a base station level as a downlink service arrives, so as to effectively reduce a paging overhead at the network side, and shorten a time delay for the service creation, without any necessity for the UE to update a paging area.